Lasso select in straight lines?
There is no polygon select tool in Blender (yet) but you can hold down CTRL after your first selection and Blender will create a path to the next vertex you right click. There are some settings in the Tool panel to adjust it's behavior. If your selection path is closed you can press H to hide, which then enables you to L link select the island. ALTH and you get the whole gang. A bit of a work around but can be handy.